A molded article formed from polyglycolic acid (hereinafter, also referred to as PGA), which is one type of aliphatic polyester, is used as a member for well drilling that requires a large compressive strength. It has been reported that the uniaxial compressive strength of a known molded article made from PGA (hereinafter, also referred to as a PGA molded article) is in a range of from 50 to 200 MPa (Patent Document 1). Note that in the present specification, the term “well” is a general term for an oil well and a gas well.